时间:2019-01-30 作者:英语课 分类:农业与发展


英语课

AGRICULTURE REPORT - Cover Crops
By Mario Ritter


Broadcast: Tuesday, March 23, 2004


This is Steve Ember with the VOA Special English Agriculture Report.


The idea to grow a crop that improves the land and prepares it for other crops is thousands of years old. But scientists continue to search for new and better ways to use what are called cover crops.


Aref Abdul-Baki is with the Agricultural Research Service of the United States Department of Agriculture. He works at the Sustainable Agricultural Systems Laboratory in Beltsville, Maryland.


Mister Abdul-Baki has found some cover crops that resist worms that attack tomatoes. These crops are sunn hemp 1, cowpea and velvet 2 bean. They are planted during the months when the main crops are not normally grown. In states with moderate climates like Maryland and Virginia, the winter months are a good time to grow cover crops.


For tomatoes, cover crops can be planted in September. They can be turned over in the soil in May. The same method can be used for other summer crops like peppers, sweet corn, green beans and some melons.


After the cover crop is cut and turned, the result is a layer of organic material. This will provide fertilizer for the new crop. Also, the cover crop provides extra nitrogen to the soil.


Cover crops mixed with soil into mulch prevents the growth of unwanted plants. It also keeps soil from drying out and prevents the loss of soil.


In hot, dry parts of California, cover crops help keep down soil temperatures. They also reduce water loss and erosion.


Mister Abdul-Baki has shown that cover crops can save farmers a lot of money. Tomato farmers, for example, have used methyl bromide to treat their soil before they plant their tomatoes. This chemical kills many kinds of organisms that harm crops. Such treatment can increase the size of the harvest. But the government restricts the use of methyl bromide. And countries have agreed to an international treaty to ban it.


Mister Abdul-Baki has found that farmers who use cover crops with tomatoes save one-thousand-four hundred dollars per hectare. Farmers save on chemicals and also fertilizer. And Mister Abdul-Baki says the farmer produce as many, or more, tomatoes per hectare as compared to no use of cover crops.


Some cover crops provide enough seed for the next growing season. This can reduce costs even more.


This VOA Special English Agriculture Report was written by Mario Ritter. This is Steve Ember.



n.大麻;纤维
  • The early Chinese built suspension bridges of hemp rope.古代的中国人建造过麻绳悬索桥。
  • The blanket was woven from hemp and embroidered with wool.毯子是由亚麻编织,羊毛镶边的。
n.丝绒,天鹅绒;adj.丝绒制的,柔软的
  • This material feels like velvet.这料子摸起来像丝绒。
  • The new settlers wore the finest silk and velvet clothing.新来的移民穿着最华丽的丝绸和天鹅绒衣服。
学英语单词
absorption reaction rate
abuse of law
acrobatic show
Aleksandrinka
Allo-PBSCT
application workspace
arbitrally
blinking method of stereoscopic viewing
brass watch case blank
Chilean tinamous
cixiid
clap-hand
common laburnum
compartment hot well
compartmentalised
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Coquimbo owl
cross platform
cyclotheric sedimentation
dc data set
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diacetylurea
dicumarols
elasto-aerodynamics
erosional vacuity
erotematic
final thermomechanicaltreatment
Gamu
general most favoured nation clause
glory of the snow
green goodss
gyroso-
hally
haylee
hofners
hydrated stock
hyperthite
idiologism
in the jug
incidental cost
ioduretted
items sample
keep on trucking
kindjals
koevoets
laminated clay
Lasianthus formosensis
leveling off
macro-observation
magmatic circulation
marine windscreen
mGal, mgal
moisture measurer for sand and stone
muscle scars
N.C.
nbcc
nobeliums
nuclenoic
NuLab
on-state characteristic
peritoneal tap
phthioic acid
plate mangle
prends
prevention of collision
prolmon tablet
pyramidal cells
raw mast
reactor coolant system cold leg isolation valve
Regranex
relative-entropy
reliability index of generating system
risto
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sit down to
solti
standard reference materials
starch ester
static stability margin
stochastic procss
strict secrecy
stupiditarian
superior characters
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symbiotic action
synedra undulata
synthetic nitrogenous fertilizer
systematic production of substitution lines
thuggish
total corneal transplantation
total variation decreasing scheme
Tuamarina
twin-screw conveyor
TWTA
ultraviolet radiations
unintentional nonlinearity
unquietous
wassily chair
wax string
y.m